Oscar Pistorius -- Chief Investigator Facing Attempted Murder Charges,,

7:55 AM PT -- Botha is out. Officials in South African have appointed a NEW lead investigator in Oscar Pistorius case.

The Oscar Pistorius case took a dramatic turn Thursday with shades of the O.J. Simpson case ... with a shocking revelation -- the lead investigator is facing attempted murder charges.

Detective Hilton Botha -- who laid out the prosecution's case earlier in the week -- allegedly shot at a minibus in 2011 and criminal charges were filed but dropped due to a lack of evidence.  But then -- 10 days before Reeva Steenkamp was killed -- authorities found new evidence and reinstated the attempted murder charges.

Now the South African prosecutor's association is urging that Botha be booted from the Pistorius case.

Botha -- who is turning out to be the Mark Fuhrman of the case (if you're under 30, Google it) -- did a lousy job under cross-examination by Pistorius' lawyers and that could create problems for the prosecution.

Meanwhile -- the judge asked Pistorius' lawyer a bizarre question which has shades of celebrity justice -- "Do you think there will be some level of shock if the accused is released [on bail]?"  The defense fired back, "I think there will be a level of shock in this country if he is not released."